provideRootContext

provideRootContext<T>(key: ContextKey<T>, create: () => T): T

Provides a value on document.documentElement, making the page-wide case the outermost scope of the same mechanism.

Usage

// Scoped or page-wide, resolved the same way, nearest first.
const channels =
  injectContextSync(el, DataChannels) ?? provideRootContext(DataChannels, () => new Map());

Parameters

• key — a ContextKey.
• create — a factory, run at most once per key.

Return value

• T — the value, created or already there.

Why it is the same mechanism

Because the value sits on document.documentElement, a request from anywhere reaches it by bubbling, and a nearer provider still wins through stopPropagation. There is no separate global registry and no second lookup path.

Lazy, and once

create runs at most once per key, and nothing is created at import time. A page that never asks for a key never builds its value.

It cannot be disposed

A root provider outlives the instance that asked for it first, because it is page state. That is the point: the first component to need a page-wide channel should not own its lifetime.

This is what replaces withGroup, which is not ported. For a scoped set of peers, use createGroup() with an ordinary provideContext().